A number of people asked me before I came away, “Where and what is Truk Lagoon?” In simple terms, Truk, though now called Chuuk is an small archipelago of islands, some 50 miles in diameter with a 140 mile circumference of reef located just north of the equator and west of the dateline in the Pacific Ocean. It became a Japanese fortified stronghold between WW1 and WW2, home to the Imperial Fleet and destroyed between the 17th and 18th February 1944 by the Americans during Operation Hailstone. Today it is a global attraction to divers who wish to visit the battleships and support vessels sunk during the attack. Here’s a little history.

During WW1, Japan joined the British in attacking the German held colony of Tsingtao, on the east coast of China in addition in 1917 to sending several escort vessels to assist the British Royal Navy in the Mediterranean. As Germany fell, the Japanese retained Tsingtao and other land as it continued its territory expansion in the need for raw materials post its victory over the Russian Baltic Fleet in 1905, with British technical assistance and warships built in British shipyards.

In 1918 and the fall of Germany, Japan was rewarded for her loan of a battalion of infantry and the naval support for the British in the Mediterranean with the Marianas Islands, Caroline Islands and most of the Marshall Islands. Although the Versailles Peace Treaty mandated no military fortifications or naval bases shall be established on these territories, Japan embarked on a fortification of Truk.

Provoked by Japan’s expansionist goals, in 1921 the Washington Navel Treaty was signed, pegging the size of the British Royal Navy and the United States Navy to a higher quota to that of Japan, France and Italy. Displeased, the British and Americans placated Japan by agreeing not to develop naval bases east of Singapore and west of Hawaii, effectively giving Japan control of a huge slice of the north west Pacific.

When Germany invaded Poland and hence triggering WW2, the military aggressive Japanese were eager to expand their empire, but with lack of oil resources, the Dutch East Indies was of specific interest. The Second Sino-Japanese War continued through WW2, where Russia supported China in hope that Japan would not attack Siberia. Scarce of her of oil and raw materials, Japan depended on exports from America through the 1930s, underpinning her war industries and aggression, which soon wore thin with the Americans. In 1939 and subsequent to continued attacks on American interests in China, the United States withdrew from the US-Japan Treaty of Commerce and Navigation and later that year, Japan organised their Fourth Fleet to protect their island holdings and made Truk Lagoon its HQ.

In early 1940 in alliance with Germany and after the fall of France, Japan demanded she move her troops from China to Vietnam and Thailand and establish military bases there. On 2nd July 1940 to curb Japanese aggression, mandating licence and prohibition of aviation fuel, iron and steel, President Roosevelt signed the Export Control Act with an embargo aimed at Japan, restricting supplies to destinations other than Britain and other western hemisphere nations.

In 1941 Japan entered the Axis Pact with Germany and Italy in September of that year, faced with her crippling trade embargoes with Britain, America and the Netherlands. Membership of this Pact ensured Germany recognised East Asia was a Japanese influence while Germany and Italy intended to establish a New Order in Europe, the Japanese doing likewise is East Asia. Germany hoped that Japan would restrain America while she targeted Britain.

Contrary to the aforementioned 1921 Washington Navel Treaty, Japan doubled its size of her naval combat tonnage than that of the British and Americans and by 1941 the Japanese Fleet was more powerful than that of the combined fleets of Britain and America, with bigger guns, well designed and armed ships together with well drilled and exercised troops. Through that year, on one hand completing war preparations, Japan was endeavouring to negotiate the cessation of the trade embargo as she would collapse within a few years from lack of raw materials. If the embargo could not be lifted, Japan would go to war and seize raw materials from South East Asia and oil from the Dutch East Indies. Friendly towards China, America would not negotiate such an agreement unless Japan withdrew forces from China, Korea and Manchuria. Japan found this unacceptable though continued negotiations until midnight on 30th November 1941.

The Japanese knew that they would not win a prolonged war, but with America moving her naval fleet to Hawaii in the Spring of 1940, it opened the door for a preventative knock out strike. She believed that if she could destroy the the US Pacific Fleet in one blow, it may provide enough time to forge a viable Pacific empire.

Having developed a torpedo that could be dropped by an aircraft and run in shallow water, in addition to noting the then recent success of the British carrier launched plane attack against the Italians at Taranto in November 1940, if an attack on Pearl Harbour could be successful, the Japanese believed they would be more than match for the remaining Allied forces in the area.

Although a tactical success for the Japanese at Pearl Harbour, strategically the attack was less significant as fuel dumps were not damaged and the four powerful American aircraft carriers had been away at sea that day. These carriers would play a pivotal role in the reconquest of the Japanese strongholds of Truk Lagoon and Palau. Rather than launch a third wave of attacks to destroy the fuel dumps and locate the aircraft carriers, Admiral Nagumo withdrew his fleet to safety, the American naval power was largely intact. Worse still, it now brought America into the war in the Pacific and Asia.